In dentistry, the agar-alginate combination impression technique is widely used as a technique for obtaining an impression of the oral cavity when preparing a prosthesis. An agar impression material is primarily used together with an alginate impression material in the one-step combination impression technique. Specifically, an agar impression material that has been liquefied and tempered to a low viscosity state is injected into a portion of the mouth where a cavity is formed after which a tray loaded with a highly viscous alginate impression material is placed in the mouth to obtain an impression.
However, because an agar impression material is a thermo-reversible gel, its initial setting time is short and working time is limited.
On the other hand, alginate impression materials may be a powder-liquid type or a two-paste type (e.g., see Patent Documents 1-5).